SkyWatcher 130P - Poor tracking (GoTo) after alignment

[newbiegazer]

Hi All,

I'm really new to all this stuff and have used my scope a few times now and loving it. Last few nights I've looked really closely at the moon and also Jupiter is looking pretty awesome at the moment.

The thing i've got a problem with is just how good is the GoTo meant to be? I've tried several times now with 2 star align and then doing PAE as well and yet when the scope slews to an object it gets close, but not close enough that its visible in the eye piece. I do the align in such a way that I think its gotta be pretty perfect... I start with 25mm and then find my first star (Polaris), get that centred then put in the barlow and get that centered and then put in the 10mm for max magnification but also to me that means it got to be perfectly alligned on that star now. Then at that point keep that set-up hit enter and select my next star which tonight was Alpheratz, something a good deal away from each other as I assume that gives the best accuracy? So got that centered in the 10mm and all done and good.

Right now tell it I want to go and look at Jupiter and it gets into the right area, but its certainly not visiable in the eye piece. I have to use the finder scope instead to get it properly centered? Is that correct, after alignment you'd still need to do that? Its just with my lack of knowledge of the night sky, to find other planets which are far less visible like Neptune/Uranus and the scope when it slews to the planet to be so far out (and nothing obvious to what is what if changing back down to the 25mm) how can I find where it is? After a while of gazing the GoTo can't even find the moon and it seems to get further lost ie still within finder but only just - so that to me seems like quite a distance out?

Is there any way to calibrate these things? I've read up on backlash a bit but not sure if that will help my problems here.

Also other couple of questions:

- I think the right way to go to get bettter magnification on this to see things like Jupiter better would be a 5mm eye piece? And read that getting a 2mm might be a bit much for the scope and will problably show a less clear picture the more its magnified by smaller eye pieces thus a 5mm would hopefully be not too bad?

- What sort of camera should I buy to fit this and does it require something to hold the camera in place or does it not put to much presure on the scope and everything is the camera is just screwed in place (guessing that it what happens, I have what I beleive is called the T-bone piece etc but not all that sure how to fit a camera yet and what might be the best type of camera to get for the scope). If anyone has pointers on that, it would be much appreciated.

Many Thanks and Much appreciated for any replies.

Happy Gazing

[ronin]

Not familiar with the scope but I guess it is on an EQ mount?

For a 130P I would assume an EQ3-2

Have you set up and aligned the mount with a polar scope?

Also I presume that you have supplied the correct data for your location.

Sorry to ask but there is no mention of this and it is therefore an unknown factor.

Next planets are a bit of a pain, they don't more at the same rate as the stars and at times they go backwards. Simply put I would not expect a fairly simple handset to actually maintain 100% accurate data for all the planets (8 excluding earth) for every year.

For some reason I would not use Polaris, try 2 stars either side of the axis but not one on it. The polar alignment of the EQ mount should have set Polaris up pretty good. Try Capella or Algol in the East then Deneb, Vega or Altair in the West.

If it is on an Alt/Az mount then really much the same holds true, set the mount up as accurately as possible before aligning the scope.

[brantuk]

When you "goto" an object and it's not in the eyepiece then yes it should appear somewhere in the finder and you can realign. This all depends on how well the finder and main tube (OTA) are aligned together and what magnification you used to do it.

For general observing in UK "seeing" 150x to 200x mag is the most common range when seeing is good. So if you can use that when aligning, the accuracy will be better. The 130P has a focal length of 650mm so a 4mm or 5mm eyepiece will line them up together nicely for the goto.

I choose alignment stars in the same 1/3rd of the sky - make a nice big triangle with them and accuracy will be fine in that area. When you move to another area of sky use the PAE - this does work and over a session overall accuracy will get better across the whole sky. HTH